Users Guide

Version Description
9.7(0.0) Introduced on the Z9500.
9.0.2.0 Introduced on the S6000.
8.3.19.0 Introduced on the S4820T.
8.3.12.0 Introduced on the S4810.
8.3.16.0 Introduced on the MXL 10/40GbE Switch IO Module.
Usage Information
The default number of 802.1p priorities that you can enable for PFC is –2. The maximum number of 802.1p
priorities that you can enable for PFC is –4. Queues to which PFC priority trac is mapped are lossless by default.
Trac may be interrupted due to an interface ap (going down and coming up) when you recongure the lossless
queues for no-drop priorities.
The default number of lossless queues supported on the switch is two. The maximum number of lossless queues
supported on the system is 4.
A PFC peer must support the congured priority trac (as DCBX detects) to apply PFC.
show dcb
Displays the data center bridging status, the number of PFC-enabled ports, and the number of PFC-enabled queues.
Syntax
show dcb
Command Modes EXEC Privilege
Command History
This guide is platform-specic. For command information about other platforms, see the relevant Dell Networking
OS Command Line Reference Guide.
Version Description
9.10(0.0) Introduced on the S6100-ON.
9.8(1.0) Introduced on the Z9100–ON.
9.7(0.0) Introduced on the S6000-ON and Z9500.
9.0.2.0 Introduced on the S6000.
8.3.19.0 Introduced on the S4820T.
8.3.12.0 Introduced on the S4810.
8.3.16.0 Introduced on the MXL 10/40GbE Switch IO Module.
Usage Information Specify a stack-unit number on the Master switch in a stack.
Example
Dell(conf)#show dcb
DCB Status: Enabled, PFC Queue Count: 2
Total Buffer: Total available buffer excluding the buffer pre-allocated
for guaranteed services like global headroom, queue's min
guaranteed buffer and CPU queues.
PFC Total Buffer: Maximum buffer available for lossless queues.
PFC Shared Buffer: Buffer used by ingress priority groups for shared usage.
PFC Available Buffer: Current buffer available for new lossless queues to be
Provisioned.
stack-unit Total Buffer PFC Total Buffer PFC Shared Buffer PFC Available Buffer
PP (KB) (KB) (KB) (KB)
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450 Data Center Bridging (DCB)